Stepping switch



J. L. BoNANNo 2,928,916

STEPPING swITcH March 15, 1960` Filed April 8, 1959 4 Sheets-Sheet 1 INV N OR 7555/34 @M9/VNO Ma, Qld/@MM ATTO R N EYS March 15, 1960 .1. L. BoNANNo STEPPING SWITCH 4 Sheets-Sheet 3 Filed April 8, 1959 dll.

March 15, 1960 J. 1 BoNANNo 2,928,916

STEPPING swI'rcH med April a, 1959 4 sheets-sheet `4 ATTORNEYS nited States Patent STEPPING SWITCH Joseph L. Bonanno, South Orange, NJ., assignor to The Lionel Corporation, New York, N.Y., a corporation of New York Application April 8, 1959, Serial No. 805,034

8 Claims. (Cl. 200-105) The present invention relates to an electrically actuated stepping switch.

Stepping switches are used where a large number of automatic switching operations are'required. A stepping switch is a controlled step-by-step selector switch having one or more movable contacts and a very large number of stationary contacts adapted to be engaged successively by the movable contacts as the switch is stepped around, generally by the application of electrical impulses to suitable actuating means for the stepping switch. Stepping switches are generally stepped in only one direction.

It is an object of the present invention to provide a stepping switch capable of being stepped in opposite directions with precision and reliability.

It is another object of the invention to provide a compact, highly dependable stepping switch capable of being actuated in both directions by the application of positive and negative current pulses thereto.

The invention will be fully understood vand other objectsy and advantages thereof will become apparent from the following description and the drawings in which:

Fig. l is an exploded perspective view of astepping switch according to theinvention; p

Fig. 2 is a top view with the contact disc removed and part of the ratchet wheel broken away and with the parts in their neutral position;

Fig. 3 is a view similar to that of Fig. 2 showing the p j 9 9 of Fig. 2;

Fig. 10 is a partial sectional view taken along the line 10-10 of Fig. 3; and

Fig. 1l is a diagrammatic view assembly. v

Referring to the drawing, cylindrical case 10 may. be formed kof an aluminum alloy or other suitable material. It includes a base 11 and sides 12 and 13 joined by a shoulder 14. A plurality of tapped bosses 16 are provided along shoulder 14. The base has a bushing 17 supporting fixed center pin 18, which may be formed of stainless steel. A permanent'magnet rotor assembly 20 is mounted on pin 18 against the bushing or bearing 17. Rotor 20 comprises a cylindrical permanent magnet 21 and an actuating plate 22- integral with a disc .23 which overlies the mganet 21. formed of Phosphor bronze and includes a pair of projecting ears 24. Magnet 21 and plate 23 are held assembled of the rotor and stator Actuating plate 22" maybe ,7o

by any suitable means such as stainless steel bushings 25 fice and 26 and the tubular sleeve 27 through which the pinV 18 passes. The rotor 20 is thus assembled and mounted as shown in Fig. 7.

A stator 30 is mounted in the lowermost portion of casing 10 around the rotor 20. The stator comprises a steel ring 31 having a tapped hole 32 into which a screw 32 is adapted to extend for holding the ring 31 fixed within the casing. A magnetizable core 33 consisting of a plurality of laminations suitably riveted or otherwise fastened together is xedly mounted in ring 31. The core 33 has a circular opening 34 for receivng rotor 20. The core has a plurality of poles which are, in the present embodiment, shown as being four poles 39-42 on which coils 35.-38 are mounted. The coils are connected in series with a pair of input leads 43 and are interconnected by wires 45, 46 and 47. The coils are so connected and wound that coils 35 and 37 will produce N-poles on the inner endsof pole pieces 39 and 41, and coils 36 and 38 will produce S-poles at the inner ends of pole pieces 40 and 42 when the current ows through the coils in one direction, and will produce the opposite magnetic polarity when the current flows in the other direction. Interme diate the four poles 39-42 the laminations are notched at 48 so as to denne distinct poles. In cooperation with the stator arrangement just described the rotor is magnetized sorthat it has two N-poles and two S-poles as shown in Fig. l1, when in its neutral position.

VOverlying the stator 30 and the rotor 20 is an assembly comprising a base plate 50 formed of a non-magnetic material such as brass. Plate 50 is fastened to the case 10 by screws 51 which enter the bosses 16. A projection 52 on case 10 helps to position the base plate. Plate 50 has a cut-out 54 and a downwardly projecting lug 55 the purpose of which will be described later. Mounted over the plate'50 is an indexing plate 60 made of a nonmagnetic material and having an opening 61 throughv Vwhich the actuating plate 52 is adapted to extend, with to move in both directions without striking pin 18. A

stud 64 in plate 60 forms a pivot for it and extends through the base plate 50 as shown in Fig. 5. The lower end of stud 64 has thereon a bushing 66 on which a centering spring 67 is mounted. The spring 67 has two side arms 68 and 69 which engage the lug 55. Thus, the centering spring 67 tends to return the indexing plate 60 to its center or neutral position when the latter is turned by the actuating plate 22. At one end, the indexing plate is provided with a pair of arms having cam surfaces 70 and 71. These surfaces are adapted to engage cam followers 73 and 74 integral with locking pawl assemblies 75 and 76. The locking pawl assemblies are mounted by means of studs 78 around which there are mounted biasing springs 79 for biasing the locking pawls 80, 81 inwardly. Pawl 80 is shaped to prevent counterclockwise v rotation and pawl 81 is shaped to prevent clockwise rotation.

At the other end of indexing plateY 60 there is an escapement 85 rcomprising indexing pawls 86 and 87. Thepawls are provided with pivots 88 and 89 and an indexing spring 90 mounted on a stud 9K1. Pins 92 and 93 are positioned for moving the pawls 86 and 87 out of engagement when the indexing plate 60 is moved in one direction or the other. A ratchet wheel 10G formed of a non-magnetic material is provided with a center bushing 101 adapted to fit over the pin 18. The diameter ot' the ratchet wheel is such that it is engaged by the indexing vpawls 86 and 87 and the locking pawls 80 and 81. On

assembly comprises a spring contact supporting bracket Patented Mar. 15, 1960 s.

106 which may be fastened by rivets 107 to the ratchet wheel. 107 to the bracket 106. The spring 108 is formed of any. suitable spring material such as silver and isprovided witha'loop it@ which engages the rounded head of..r

center pin 18. The upper end of bracket 106 supports the spring contact 110 which has a pair of arms k111 'and 112 and is preferably formed of sterling silver'.` Arms 111 and 112 are adapted to engage the lower ends 115. and 116 of two or more circular rows of lugs or terminals 118 and 119 of a iixed Contact disc 120y so as to intermore of the terminals 119. arrangements of terminals and spring contacts Ycan be used. The case may be crimped atits upper edge to hold disc 120 xed.

The operation of the vstepping switch is as follows; When no current is supplied to theleads43 and coils 35.--38 are not energized, indexing plate 60 is held in a neutral or center position by'means of spring 67. In this position the rotor is oriented with respect to the stator as shown in Fig. ll and Fig. 6. When current or a current pulse in one direction is supplied to the stator coils they produce a magnetic field as indicated by the lines 120 of Fig. ll causing the rotor to rotate in one direction. Actuating plate 22 xed tothe rotor is there# fore moved, turning the indexing plate .60, say, in the clockwise direction. As indicated in Fig. 3, the indexing plate is thus pivoted about the stud 64 and'moves the escapement ina clockwise direction, causing. indexing pawl 86 to move outof engagement with pin 92 and A centerspring 108 is also fastened by rivetsk ing said ratchet wheel for locking it against rotation in either direction, means on said indexing plate for actuating said locking pawls and switching means including stationary circumferentially arranged contacts and a cooperating contact mounted on said ratchet wheel for engagement with the stationary contacts.

2. A stepping switch according. to claim l, wherein each locking pawl has spring means biasing it against the ratchet wheel and the actuating means for said pawls include a cam follower xed to each pawl and a pair of cam surfaces on the indexing platepositioned to engage said cam followers.

l 3. A stepping switch comprising a casinga stator assembly in said casing, said stator assembly including a mulit-pole magnetic `core having a circular opening and a plurality of interconnected coils mounted on the poles of the stator and a permanent magnet rotor in said opening, means for mounting said rotor for oscillation about an axis of said circular opening, an indexing plate, means for pivotally mounting said indexing plate, means connecting said indexing plate to said rotor, spring means for urging said indexing plate to a center position,.an escapement connected to one end of said indexing plate, and'a ratchet wheel pivotally mounted on said axis in.

engagement with said escapement for rotating said ratchet" wheel one tooth at a. time in response to oscillation of the indexing plate, and switching means including sta:

.tionary circumferentially arranged contacts anda co.-`

into engagement with ratchet wheel 100, thusmoving` the ratchet wheel in the clockwise direction. Simultaneously, the camming surface 71 of indexing plate 60 moves the locking pawl S1 out of engagement with the ratchet wheel in"order to permit the latter to rotate.k At the same time the camming surface 70 moves out of engagement with the vcam follower 73 and permits the locking pawl` 80.to engage the ratchet wheel 100 so as 'to prevent counterclockwise rotation and to limit the rotationof ratchet wheel 100 so that it moves only'a distance of one tooth. Accordingly, the spring contact assembly 10S is also moved to switch the connections with terminals 118 and'119. Inthis manner the switchperforms one step for each pulse which is applied, regardless. of the length of the pulse or its magnitude, and the number of tions4 and modifications thereof may be made withoutV departing from the spirit andscope of my invention asv defined inthe following claims..

What is claimed is:

1. A stepping switch comprising a casing, `a stator assembly in said casing, said stator assembly including a multi-pole magnetic core having a circular opening and a plurality of Yinterconnected coils mounted on the poles of the stator7 a permanent magnet rotor in said opening, means for mounting said rotor for oscillation about Yan axis of said circular opening, an indexing plate, means.

for'pivotally vmounting said indexing plate, means connecting said indexing plate to said rotor, spring means for `urging said indexing plate to a center position, an escapement connected to. one end of said indexing plate and la ratchet wheel pivotally mounted onsaid axis in engagement With said escapement for rotating said ratchet Wheel one tooth at. a time in responseto oscillation of theindexingplate, a pair of locking pawl means engag-.l

operating contact .connected to said ratchet wheel -for engagement with the stationary contacts.

4. A stepping switch comprising a casing, a .stator assembly insaid casing-said stator assembly including a multi-pole core having a circular opening and a plurality of interconnected coils mounted on the poles. of the stator, a disc shaped permanent. magnet rotor having alternating N and` S poles round its circumference, means for mounting said rotor in the. opening of saidstator for oscillation about an axis of .said circular opening,.an. indexing plate, means for pivotally mounting said index.'v

ing plate, means connecting said indexing plate to said rotor, spring means for urging said indexing plate .to a center position, an escapement connected to one` end of said indexing plate, and a ratchet `wheel pivotally mounted. on.said axis in engagement. with said. escapement for rotating said .ratchet wheel one tooth at a time in response .to oscillationof theindexing plate, and

switching means... including.` stationary circumferentially Y arranged contacts and a cooperating contact connected to said ratchet wheel for engagement with the stationary. contacts.

5. A stepping switch comprising a casing, a stator as'- sembly insaid casing, said stator assembly includinga multi-pole magnetic core having a circular opening and.

a plurality. of vinterconnected coilsmounted .on the poles ofthe stator, a vpermanent magnet rotor, means for mounting said rotorin said opening for .oscillationabout an axis of said'circular opening, an escapement, a ratchet wheel pivotally mounted on said .axis inengagement with said escapement, means connecting said escapement Yto said rotor for rotating said. ratchet wheel one tooth at a time in response'to oscillation of the indexing plate, and. switching means including stationary contacts and a cooperating contact connected to said ratchet wheel for engagement with the stationary contacts. i

6. A stepping switch according ,to claim 5, including` a pair of locking pawl means engaging said ratchet wheel for locking it against rotation in one direction.

7. A-.stepping switch according to claim 6 including means 'connected to said rotor'formoving one of lock-'- ing ,pawls from one tooth of the ratchet wheel to the nexttoothin response to each oscillation of the rotor.

8.'A stepping,switchcomprising Ma cylindrical casing, a'stator` assembly in said casingysaid stator assembly including a `closed magnetic ring 'on a unitary'A core having a .pluralityof .radially extending polesV -iand a circular opening and a plurality of interconnected coils mounted on the poles of the stator, a permanent magnet rotor having a like plurality of circumferentially arranged poles, means for mounting said rotor for oscillation about :an axis of said circular opening, an indexing plate, means for pivotally mounting said indexing plate, means connecting said indexing plate to said rotor, spring means for urging said indexing plate to a center position, an escapement connected to one end of said indexing plate, and

a ratchet wheel pivotally mounted on said axis in engage- 10 No references cited. 

